Fantasy and Science Fiction Writing

What Exoplanets Can Tell Us About Building Science Fiction Worlds

1. Planets exist around other stars.
2. The dividing line between planets and stars is a lot more blurred than we thought it would be: some very large planets have been found that do not appear to have dueterium (heavy hydrogen) fusion occurring and therefore are not brown dwarfs. There are also some very small brown dwarfs with methane in their atmospheres that look a lot like large gas giant planets.
3. Gas giant planets can exist very close to their stars. This was thought to be impossible, but the first exoplanet discovered around a main sequence star was one of these ‘hot jupiters’.
4. Planetary systems containing multiple planets exist around other stars.
5. Both rocky planets and gas giants exist around other stars.
6. Planets can exist in systems containing multiple stars.
7. Planets can exist in the middle of interstellar space with no star nearby. Such planets are believed to have formed around a star and then been ejected from the system.
8. There is an amazing variety of planetary systems.
9. Planets are found circling brown dwarfs.
10. Planets are found circling other planets.
11. Planets are found circling red dwarves.
12. Planets are found circling pulsars.
13. Planets down to twice the mass of Earth and planets much larger than Jupiter exist circling other stars.

What the Exoplanets Discovered So Far Cannot Tell Us:

1. If life exists on any of the planets discovered so far.
2. The ratio of small planets to large planets – smaller planets are much harder to find and cannot be found at all with many current techniques.
3. The ratio of stars with planets to stars without.
4. The total number of planets in a given system.
5. Anything about any moons present.

What does this mean for science fiction writers who want to get their facts straight?

1. You can still posit small planets around a star and nobody can tell you you’re wrong – although this may change with time.
2. With all these strange planets and planetary systems, you have many new options for settings. Do something weird and interesting – I get very tired of all the earth clones seen in science fiction.
3. You can set a story on a planet that is known to exist around another star.

Sources:

The Astrobiology Web http://www.astrobiology.com/

Space Ref. http://www.spaceref.com/